Here’s a link to a page on the official website of the Chinese Olympic Committee with a nice summary of Yang Style taijiquan. I know there was some discussion here a while ago about taijiquan in the Olympics.

If you don’t have Chinese fonts installed on your computer, just click “cancel” if a window appears about installing the fonts. The pages are in English, and you should have no trouble viewing them. I haven’t yet read through all of these pages carefully, but they seem to contain some good information, geared toward the general public rather than experts.